Created Unassigned: R.Net Error: could not find function "memory.limit" [175]

Hi, I have the following lines of code in C#:

string RpathOld = @"C:\Program Files\R\R-3.1.0\bin\x64";
string RpathNew = @"C:\Program Files\R\R-3.2.0\bin\x64";

try { REngine.SetEnvironmentVariables(RpathOld); }
catch { REngine.SetEnvironmentVariables(RpathNew); }

REngine engine = REngine.GetInstance();

But when it runs the last line I get an error:

An unhandled exception of type 'RDotNet.EvaluationException' occurred in RDotNet.dll

Additional information: Error: could not find function "memory.limit"

How can I solve this? I have tried to run the function "memory.limit()" in R and it works, giving me the RAM memory size.
Is there something I could to do to make R.Net work? Thanks.